/* 
   switch语句
      语法:  switch(表达式值){
                 case 值1:
                    语句块1
                    [break]
                 case 值2:
                    语句块2
                    [break]
                 case 值3:
                    语句块3
                    [break]
                default:
                    块句块
             }

*/
console.log('开始程序');

switch(6){
    case 1:
        console.log('1');
        break;
    case 2:
        console.log('2');
        break;
    case 3:
        console.log('3');
        break;
    default:
        console.log('默认值');
}

console.log('结束程序');
